appendicitis – a painful swelling of the appendix (a finger-like pouch connected to the large intestine) which usually causes pain on the lower right-hand side of your abdomen (tummy)

peritonitis – inflammation of the peritoneum (the thin layer of tissue that lines the inside of the abdomen); it causes sudden abdominal pain that gradually becomes more severe and requires immediate medical treatment

a urinary tract infection – you'll probably also have pain or a burning sensation when you urinate, and you may need to urinate more often

Common causes of chronic pelvic pain

chronic pelvic inflammatory disease – a bacterial infection of the womb, fallopian tubes or ovaries, which often follows a chlamydia or gonorrhoea infection and needs immediate treatment with antibiotics